[Mlir-commits] [mlir] [MLIR][LLVM] Avoid duplicated module flags in the export (PR #131627)

Christian Ulmann llvmlistbot at llvm.org
Mon Mar 17 08:17:19 PDT 2025


https://github.com/Dinistro created https://github.com/llvm/llvm-project/pull/131627

This commit resolves an issue in the LLVMIR export that caused the duplication of the "Debug Info Version" module flag, when it was already in MLIR.

>From 0b4a9005fc9c85aeaa9d0fdbaec098756b7ac733 Mon Sep 17 00:00:00 2001
From: Christian Ulmann <christian.ulmann at nextsilicon.com>
Date: Mon, 17 Mar 2025 15:14:52 +0000
Subject: [PATCH] [MLIR][LLVM] Avoid duplicated module flags in the export

This commit resolves an issue in the LLVMIR export that caused the
duplication of the "Debug Info Version" module flag, when it was already
in MLIR.
---
 mlir/lib/Target/LLVMIR/DebugTranslation.cpp  | 28 +++++++++-----------
 mlir/lib/Target/LLVMIR/DebugTranslation.h    |  4 +--
 mlir/lib/Target/LLVMIR/ModuleTranslation.cpp |  4 +++
 mlir/test/Target/LLVMIR/llvmir-debug.mlir    |  8 +++---
 mlir/test/Target/LLVMIR/llvmir.mlir          | 15 +++++++++--
 mlir/test/Target/LLVMIR/nvvmir.mlir          |  8 +++---
 6 files changed, 40 insertions(+), 27 deletions(-)

diff --git a/mlir/lib/Target/LLVMIR/DebugTranslation.cpp b/mlir/lib/Target/LLVMIR/DebugTranslation.cpp
index 1d3ed6f3262f9..2af3ae0bd7f4f 100644
--- a/mlir/lib/Target/LLVMIR/DebugTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/DebugTranslation.cpp
@@ -32,31 +32,29 @@ DebugTranslation::DebugTranslation(Operation *module, llvm::Module &llvmModule)
   if (!module->walk(interruptIfValidLocation).wasInterrupted())
     return;
   debugEmissionIsEnabled = true;
+}
+
+static constexpr StringRef kDebugVersionKey = "Debug Info Version";
+static constexpr StringRef kCodeViewKey = "CodeView";
 
+void DebugTranslation::addModuleFlagsIfNotPresent() {
   // TODO: The version information should be encoded on the LLVM module itself,
   // not implicitly set here.
 
   // Mark this module as having debug information.
-  StringRef debugVersionKey = "Debug Info Version";
-  if (!llvmModule.getModuleFlag(debugVersionKey))
-    llvmModule.addModuleFlag(llvm::Module::Warning, debugVersionKey,
+  if (!llvmModule.getModuleFlag(kDebugVersionKey))
+    llvmModule.addModuleFlag(llvm::Module::Warning, kDebugVersionKey,
                              llvm::DEBUG_METADATA_VERSION);
 
-  if (auto targetTripleAttr = module->getDiscardableAttr(
-          LLVM::LLVMDialect::getTargetTripleAttrName())) {
-    auto targetTriple =
-        llvm::Triple(cast<StringAttr>(targetTripleAttr).getValue());
-    if (targetTriple.isKnownWindowsMSVCEnvironment()) {
-      // Dwarf debugging files will be generated by default, unless "CodeView"
-      // is set explicitly. Windows/MSVC should use CodeView instead.
-      llvmModule.addModuleFlag(llvm::Module::Warning, "CodeView", 1);
-    }
+  const llvm::Triple &targetTriple = llvmModule.getTargetTriple();
+  if (targetTriple.isKnownWindowsMSVCEnvironment()) {
+    // Dwarf debugging files will be generated by default, unless "CodeView"
+    // is set explicitly. Windows/MSVC should use CodeView instead.
+    if (!llvmModule.getModuleFlag(kCodeViewKey))
+      llvmModule.addModuleFlag(llvm::Module::Warning, kCodeViewKey, 1);
   }
 }
 
-/// Finalize the translation of debug information.
-void DebugTranslation::finalize() {}
-
 /// Translate the debug information for the given function.
 void DebugTranslation::translate(LLVMFuncOp func, llvm::Function &llvmFunc) {
   if (!debugEmissionIsEnabled)
diff --git a/mlir/lib/Target/LLVMIR/DebugTranslation.h b/mlir/lib/Target/LLVMIR/DebugTranslation.h
index 930e6a2672136..b690d4820d7b0 100644
--- a/mlir/lib/Target/LLVMIR/DebugTranslation.h
+++ b/mlir/lib/Target/LLVMIR/DebugTranslation.h
@@ -31,8 +31,8 @@ class DebugTranslation {
 public:
   DebugTranslation(Operation *module, llvm::Module &llvmModule);
 
-  /// Finalize the translation of debug information.
-  void finalize();
+  /// Adds the necessary module flags to the module, if not yet present.
+  void addModuleFlagsIfNotPresent();
 
   /// Translate the given location to an llvm debug location.
   llvm::DILocation *translateLoc(Location loc, llvm::DILocalScope *scope);
diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index 05245c7212169..1e2f2c0468045 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -2223,6 +2223,10 @@ mlir::translateModuleToLLVMIR(Operation *module, llvm::LLVMContext &llvmContext,
   // See https://llvm.org/docs/RemoveDIsDebugInfo.html
   translator.llvmModule->setIsNewDbgInfoFormat(UseNewDbgInfoFormat);
 
+  // Add the necessary debug info module flags, if they were not encoded in MLIR
+  // beforehand.
+  translator.debugTranslation->addModuleFlagsIfNotPresent();
+
   if (!disableVerification &&
       llvm::verifyModule(*translator.llvmModule, &llvm::errs()))
     return nullptr;
diff --git a/mlir/test/Target/LLVMIR/llvmir-debug.mlir b/mlir/test/Target/LLVMIR/llvmir-debug.mlir
index d15274311d745..ab39a29515cc2 100644
--- a/mlir/test/Target/LLVMIR/llvmir-debug.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir-debug.mlir
@@ -316,8 +316,8 @@ llvm.func @dbg_intrinsics_with_no_location(%arg0: i32) -> (i32) {
 
 // CHECK: @global_with_expr_1 = external global i64, !dbg {{.*}}
 // CHECK: @global_with_expr_2 = external global i64, !dbg {{.*}}
-// CHECK: !llvm.module.flags = !{{{.*}}}
-// CHECK: !llvm.dbg.cu = !{{{.*}}}
+// CHECK-DAG: !llvm.module.flags = !{{{.*}}}
+// CHECK-DAG: !llvm.dbg.cu = !{{{.*}}}
 // CHECK-DAG: ![[FILE:.*]] = !DIFile(filename: "not", directory: "existence")
 // CHECK-DAG: ![[TYPE:.*]] = !DIBasicType(name: "uint64_t", size: 64, encoding: DW_ATE_unsigned)
 // CHECK-DAG: ![[SCOPE:.*]] = distinct !DICompileUnit(language: DW_LANG_C, file: ![[FILE]], producer: "MLIR", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: ![[GVALS:.*]])
@@ -336,8 +336,8 @@ llvm.mlir.global external @global_with_expr_2() {addr_space = 0 : i32, dbg_exprs
 // -----
 
 // CHECK: @module_global = external global i64, !dbg {{.*}}
-// CHECK: !llvm.module.flags = !{{{.*}}}
-// CHECK: !llvm.dbg.cu = !{{{.*}}}
+// CHECK-DAG: !llvm.module.flags = !{{{.*}}}
+// CHECK-DAG: !llvm.dbg.cu = !{{{.*}}}
 // CHECK-DAG: ![[FILE:.*]] = !DIFile(filename: "test.f90", directory: "existence")
 // CHECK-DAG: ![[TYPE:.*]] = !DIBasicType(name: "integer", size: 64, encoding: DW_ATE_signed)
 // CHECK-DAG: ![[SCOPE:.*]] = distinct !DICompileUnit(language: DW_LANG_Fortran95, file: ![[FILE]], producer: "MLIR", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: ![[GVALS:.*]])
diff --git a/mlir/test/Target/LLVMIR/llvmir.mlir b/mlir/test/Target/LLVMIR/llvmir.mlir
index ca06b26b03409..5a1f43ba1d018 100644
--- a/mlir/test/Target/LLVMIR/llvmir.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir.mlir
@@ -2774,11 +2774,22 @@ module {
                      #llvm.mlir.module_flag<max, "frame-pointer", 1>]
 }
 
-// CHECK: !llvm.module.flags = !{![[#DBG:]], ![[#WCHAR:]], ![[#PIC:]], ![[#PIE:]], ![[#UWTABLE:]], ![[#FrameP:]]}
+// CHECK: !llvm.module.flags = !{![[#WCHAR:]], ![[#PIC:]], ![[#PIE:]], ![[#UWTABLE:]], ![[#FrameP:]], ![[#DBG:]]}
 
-// CHECK: ![[#DBG]] = !{i32 2, !"Debug Info Version", i32 3}
 // CHECK: ![[#WCHAR]] = !{i32 1, !"wchar_size", i32 4}
 // CHECK: ![[#PIC]] = !{i32 8, !"PIC Level", i32 2}
 // CHECK: ![[#PIE]] = !{i32 7, !"PIE Level", i32 2}
 // CHECK: ![[#UWTABLE]] = !{i32 7, !"uwtable", i32 2}
 // CHECK: ![[#FrameP]] = !{i32 7, !"frame-pointer", i32 1}
+// CHECK: ![[#DBG]] = !{i32 2, !"Debug Info Version", i32 3}
+
+// -----
+
+// Verifies that the debug info version is not added twice, if it's already present initially.
+
+module {
+  llvm.module_flags [#llvm.mlir.module_flag<warning, "Debug Info Version", 3>]
+}
+
+// CHECK: !llvm.module.flags = !{![[#DBG:]]}
+// CHECK: ![[#DBG]] = !{i32 2, !"Debug Info Version", i32 3}
diff --git a/mlir/test/Target/LLVMIR/nvvmir.mlir b/mlir/test/Target/LLVMIR/nvvmir.mlir
index a3a70fcebb7c7..f39aca95b918f 100644
--- a/mlir/test/Target/LLVMIR/nvvmir.mlir
+++ b/mlir/test/Target/LLVMIR/nvvmir.mlir
@@ -646,8 +646,8 @@ llvm.func @kernel_func() attributes {nvvm.kernel, nvvm.maxntid = array<i32: 1, 2
 // -----
 // CHECK: define ptx_kernel void @kernel_func
 // CHECK: !nvvm.annotations =
-// CHECK: !1 = !{ptr @kernel_func, !"grid_constant", !2}
-// CHECK: !2 = !{i32 1}
+// CHECK: !{{.*}} = !{ptr @kernel_func, !"grid_constant", ![[ID:[[:alnum:]]+]]}
+// CHECK: ![[ID]] = !{i32 1}
 llvm.func @kernel_func(%arg0: !llvm.ptr {llvm.byval = i32, nvvm.grid_constant}) attributes {nvvm.kernel} {
   llvm.return
 }
@@ -655,8 +655,8 @@ llvm.func @kernel_func(%arg0: !llvm.ptr {llvm.byval = i32, nvvm.grid_constant})
 // -----
 // CHECK: define ptx_kernel void @kernel_func
 // CHECK: !nvvm.annotations =
-// CHECK: !1 = !{ptr @kernel_func, !"grid_constant", !2}
-// CHECK: !2 = !{i32 1, i32 3}
+// CHECK: !{{.*}} = !{ptr @kernel_func, !"grid_constant", ![[ID:[[:alnum:]]+]]}
+// CHECK: ![[ID]] = !{i32 1, i32 3}
 llvm.func @kernel_func(%arg0: !llvm.ptr {llvm.byval = i32, nvvm.grid_constant}, %arg1: f32, %arg2: !llvm.ptr {llvm.byval = f32, nvvm.grid_constant}) attributes {nvvm.kernel} {
   llvm.return
 }



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